The Aptera Forum
This question hasn't been fully answered yet, but there are technical papers that say it is primarily a matter of tuning spring rates and damping of a normal suspension. You can also watch videos of the Lordstown pickup platform, which uses Elaphe Wheel motors on a torture test track. I am convinced that it won't be too bad.
For rough road handling, the primary effect of wheel mass is from its proportion of total vehicle mass, so hub motor mass is at least partially offset by battery mass. Each 50Lb hub motor is less than 2.3% of the 2,200Lb weight spec.
Aptera's answer*: "It is accounted for and largely offset by using other lightweight materials in those areas. But we haven't had enough testing compare against our previous driveshaft driven version. Our initial impressions; having the motor weight out on the wheels makes this very light vehicle "feel" more grounded than the previous versions. But we will have more info on this as our testing continues."
*Cell B92 of Aptera FAQ Spreadsheet
How it feels will depend on the damper settings. I'd guess it will not feel "light" weight. If you have ever replaced 18" wheels with 20" wheels, you will feel the extra weight on rebound of the shocks. I think it may feel similar to that. Or maybe if you have driven a 3/4 ton pickup or big suv, they have heavy wheels/ tires (~80lbs) that are similar to the Aptera.
There is need for extra stiffness in the shocks to control the motion of the wheel weight, so I doubt it will feel like a typical car.
It looks like Aptera has chosen light weight wheel and tires to offset the heavy wheel motors to minimize the effect as best they can.
I have converted a 250cc motorcycle to electric 8kW hub motor.
The wheel was 11Kg heavier than the original. There are rough roads here in country NSW/ Australia but I could not detect a difference in ride comfort (the rear suspension part).
There is a white paper on this published about 10 years ago that claimed that most of the difference could be accounted for with suspension tuning of spring rates and damping.
One thing for sure is that you now have a 3 track vehicle so that going straight you have to plan for that center wheel. Rockclimbing may actually end up to be simpler esp if you install a rear wheel camera.
Good point! No rear diff clearance needed, there's a wheel there!